Hitachi, Ltd.

Mercian Corporation

Masaya Nakata

Kohei Ishizuka

Tamio Takeuchi

Teruhisa Azumaguchi

Tsutomu Kohno

Akisada Moriguchi

Hiroki Irie

Atushi Miura

Junji Takeda

A method of preparing optically active isocoumarin-3-yl-acetic acid derivatives represented by Formula (I):wherein a specific isocoumarin-ketene derivative is subjected to an addition reaction with an optically active alcohol, and then the ester thus obtained is subjected to a hydrolysis reaction. An intermediate for synthesis used therein. A method of preparing isocoumarin-3-yl-acetic acid derivatives represented by Formula (III):wherein a specific isocoumarin derivative is subjected to an addition reaction with carbon monoxide and oxygen in the presence of a transition metal catalyst. An intermediate for synthesis used therein.

Preparation of isocoumarin derivatives and intermediates for the synthesis thereof

A light transmission module is disclosed, having a light receiving element module, in which a photodiode and a coupling portion between the photodiode and a first optical fiber are hermetically sealed, and a light emitting element module, in which a laser diode driven by an electric signal and a coupling portion between said laser diode and a second optical fiber are also hermetically sealed. A two-sided print board is provided, on the two sides of which electric circuits for a transmitting system and a receiving system are mounted. The electric circuits for the transmitting and receiving circuits are; isolated electrically from each other, and are sealed in one body by molds, and accommodated in cases, together with the light receiving element module and the light emitting element module.

Light transmission module

Growing community of inventors

Yokohama, Japan

Masaya Nakata